In the evolution of the Windows client, Windows Vista Service Pack 1 is a step set firmly between Windows XP SP2 and Windows 7, just as well as the RTM version of the operating system.

But while Vista RTM's Wow-less aura has managed to sell just 140 million licenses of the platform at over a year since the launch, shaving over $1 billion off the Windows Client division revenue in the third quarter of 2008, compared with Q3 2007, SP1 is starting to send out a feeling of inevitability in terms of upgrades/migrations.

Outside of Apple's Mac OS X and Linux, there are but two solutions to "avoid" Vista SP1, for both end users and businesses, namely XP SP3 and Windows 7. However, neither can accurately justify jumping the Vista SP1 phase by themselves. On top of the fact that SP3 brings almost nothing new compared to SP2, Microsoft is also getting ready to yank the product from retail and OEM sales as of June 30. These are the most compelling "incentives" for customers looking to either XP or Vista to choose the latter.

However, just because XP SP3 won't continue to be available via Direct retail and OEM licensing starting with the summer of 2008 does not mean that the operating system will be out of reach. In fact, original equipment manufacturers are planning to use the downgrade rights associated with business editions of Vista in order to continue supplying XP to customers. In this regard, business users will still have an alternative to Vista SP1 in XP SP3 even after June 30. But while it won't offer anything much on top of SP2, XP SP3 will play well with IT infrastructures where migrating to Vista will be synonymous with a large investment that doesn't necessarily justify itself given the proximity of Windows 7.

The next iteration of Windows, currently scooped for 2010, with the possibility of arriving as early as 2009, according to Bill Gates, presents another reason for Windows users to skip Vista SP1 altogether. But the decision of going straight for Windows 7 means placing a bet on the unknown, as there are no guarantees that the lessons leaned by Microsoft with Vista will resonate in the next version of Windows. Microsoft CEO Steve Ballmer did emphasize the fact that Windows 7 would be a continued evolution, and that the ubiquitous Windows XP would be left further behind, but concrete details about the operating systems are missing entirely at this point in time.

Market analysis company Forrester Research presented Microsoft's bad history with an unpredictable release schedule for its Windows clients as the most compelling argument when it comes down to embracing Vista SP1 rather than waiting for Windows 7. But with Steven Sinofsky, Senior Vice President, Windows and Windows Live Engineering Group, while all details related to Windows 7 are blank, the delivery date, still officially not announced but confirmed for no later than 2010, is set in stone. And that is simply because Sinofsky has a strong history of meeting deadlines.